Apparatus for two-directional feed of perforated tapes



G. VORBA'CH APPARATUS FOR TWO-DIRECTIONAL FEED OF PERFORATED TAPES FiledJan. 25. 1968 2 Sheets-Sheet 1 ERROR SCANNING DEVICE Dec. 9,

c. VORBACH APPARATUS FOR TWO-DIRECTIONAL FEED OF PERFORATED TAPES FiledJan. 25, 1968 Fig. 2

2. Sheets-Sheet 2 PERFORATION STAMPING VERTICAL POSITION 0F GEAR 8FORWARD FEEDING GEAR 8 FORWARD TO REVERSE FEEDINGmllllllllllll/lllllll/l,

GEAR 8 REVERSE FEEDING GEAR 8 REVERSE T0 FORWARD FEEDING GEAR 8 MAGNET23 ARMATURE BLADE 24 United States Patent O 3,482,752 APPARATU FORTWO-DIRECTIONAL FEED F PERFORATED TAPES Gunther Vorbach,Schloss-Siedlung, Germany, assrgnor to Siemens Aktiengesellschaft FiledJan. 25, 1968, Ser. No. 700,456 Claims priority, application Germany,Feb. 1, 1967, S 108,115 Int. Cl. B6511 17/40, 43/00 US. Cl. 22651 8Claims ABSTRACT OF THE DISCLOSURE A tape advancing gear is moved betweenengaging and disengaging positions with respect to perforated tape. Amechanism shifts the gear back and forth in the forward and reversedirections and the direction of tape feed is determined by the intervalduring which the gear is engaged and disengaged. The shifting mechanismincludes two cams mounted on a drive shaft and transposed with respectto their angular position. The cams act on associated shift levers tocoordinate the timing of the forward and reverse movements of the gearwith the engagement and disengagement of the gear. One or the other ofthe two levers is rendered inoperative by a blocking mechanism todetermine whether the feed of the tape is in the forward or reversedirections.

BACKGROUND OF THE INVENTION Apparatus have been known in the past whichprovide two directional feed of perforated tape, however, they haverequired a great amount of energy for reversing the direction ofadvancement. Moreover, the reversal takes place quite slowly since twopairs of cams have had to be shifted axially.

Accordingly, it is the object of the invention to provide an advancingmechanism which provides fast feeding of perforation tapes or perforatedcards at a speed of about 30 characters per second with great separationaccuracy. It is also an object to provide an apparatus which permits areversal of the direction of advancement with a very low expenditure ofenergy, within the shortest possible period of time and which permitsthe reversal to be remotely controlled.

SUMMARY The invention relates to an apparatus for feeding perforationtapes in either a forward or reverse direction and includes a tapeadvancing gear which is mounted for cyclical engagement anddisengagement with the perforations of the tape. A first lever isprovided for advancing the tape advancing gear in a forward directionwhen the tape advancing gear is in engagement with the tape; and asecond lever is provided for advancing the tape advancing gear in aforward direction when the tape advancing gear is disengaged from thetape. The tape advancing gear is biased in a direction opposite to theadvancement imparted thereto by the levers to return the tape advancinggear after each cycle. The first and second levers are normally biasedtoward an operative position with respect to the tape advancing gear andfacilities are provided for blocking one or the other of the levers torender one of the levers inoperative during each feeding cycle. A driveshaft having two spaced cams which are transposed with respect to theirangular position is provided to alternately urge the levers away fromsaid tape advancing gear. Facilities are provided for controlling the bocking device to determine which of the levers is rendered inoperativeand thereby control whether the tape is advanced in a forward or areverse direction.

DRAWINGS Other objects, advantages and aspects of the invention willbecome apparent by reference to the following detailed description ofthe invention and drawings of a specific embodiment thereof, wherein:

FIG. 1 is a perspective view showing an apparatus for two directionalfeed of a perforated tape in conjunction with a perforation device; and

FIG. 2 is a time-motion diagram showing the relative movement withrespect to time of the various mechanical and electrical elementsdisclosed in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 there is schematicallyshown a perforation device 1 for eight-code perforation tape orcorresponding perforation tape cards. The feed system for advancing atape 33 is controlled by a shaft 2 in association with the variouscooperating elements which will hereafter be described in detail.

The shaft 2 is coupled for start-stop operation every one-halfrevolution (30 milliseconds) by a drive mechanism (not shown) in acounter-clockwise direction (FIG. 1). In order to raise and lower(engage and disengage) a tape advancing gear 8, there is provided a cam3 mounted on the shaft 2. The cam 3 acts against a roller 4 which ismounted on a rail 7 which rotates around a stationary axis 6. A tensionspring 5 normally urges the rail 7 in a counter-clockwise direction(FIG. 1) to urge the tape advancing gear 8 into engagement with theperforations of the tape. The cam 3 is effective to disengage the gear 8cyclically during the return stroke of the gear.

The tape advancing gear 8 is rotatable around an axis 9 which is alsomounted on the rail 7. The upper end portion 8a of the tape advancinggear 8 is controlled by two limit stops 10 and 11. The positioning ofthe limit stops 10 and 11 can be adjusted by rotation of eccentricsupports 36 and 37, respectively. A torsion spring 12 normally urges thetape advancing gear 8 to the right toward limit stop 10, insofar as thegear 8 is not influenced by other forces.

The tape advancing gear 8 includes at its lower end a pressure plate 812which cooperates with two control levers 14 and 15 mounted on an axis13. The control levers 14 and 15 are provided with rollers 16 and 17,respectively, which are operated by cams 18 and 19, respectively,affixed to the shaft 2. The earns 18 and 19 are transposed with respectto each other in their angular position and are shaped differently. Thecontrol levers 14 and 15 are each biased in a counterclockwise direction(FIG. 1) by tension springs 20 and 21, respectively. When the controllevers 14 and 15 are not blocked from engagement with the pressure plate812, the respective tension springs 20 and 21 are effective to exert acounterclockwise turning moment on the tape advancing gear 8 which isabout twice as high as the clockwise turning moment of the torsionspring 12.

The control levers 14 and 15 must be coordinated so that only one or theother is operative at a given time or for a given cycle. In thearrangement shown the control lever 14, when operative, advances thetape 33 in a forward direction, and the control lever 15, whenoperative, advances the tape 33 in a reverse direction. A double actingmagnetic system 23 having an armature 22 and a blade or tongue 24 iseffective to render one of the control levers 14 and 15 operative whilerendering the other inoperative. The blade 24 is fixedly connected tothe armature 22 and is movable between two stationary limit stops 26 and27 while resting on a support 25. There is also provided a dead centerspring 30 on a stationary support 29 which is located in such a way thata connecting line runs between the support and a rotary bolt 28approximately centered between the limit stops 26 and 27. This providesfor a short mechanical switching time of only about 0.5 to 1millisecond. This short period of time results from the double actingmagnetic system which has a very small load.

The control levers 14 and 15 sense the position of the armature blade 24with their arms (unnumbered) so that in each case one of the controllevers can descend while the other supports itself on the blade 24. Aset of spring contacts 32 is operated by an additional cam 31 which ismounted on the shaft 2. The spring contact 32 effectuates theenergization of the magnet 23 in cooperation with the approaching of theright angle position of the shaft 2. The tension springs 20 and 21 aswell as the torsion spring 12 are designed in the enample beingdescribed for a tape or card advancing of 100 grams.

The system is designed so that an advancement of the tape in a reversedirection can be rapidly elfectuated. This high speed reversal is veryadvantageous when combined with an error scanning device 38, of knowndesign. The error scanning device 38 is electrically connected to thespring contacts 32 in order to send a reverse signal to the magnet 23upon any error in perforation. In this way the error scanning device 38is operable to reverse the direction of feed in the next perforationcycle after sensing an error.

OPERATION The operation of the device will now be described withreference being made to the time-motion diagram shown in FIG. 2.Approximately 3 milliseconds after the coupling of the perforator shaft2, the perforation stamping commences (see line a) whereby theperforation tape 33 is grasped at least by a perforator stamp 34 for theperforation feeding. This occurs for a period of 15 milliseconds, i.e.,until 18 milliseconds after the initiation of the coupling of theperforator shaft 2. The code perforation stamps are not shown in thedrawing for reasons of sim= plicity.

At a point in time at 4 milliseconds the tape advancing gear 8 iswithdrawn from the perforations of the tape by the rail 7 and cam 3. Thetape advancing gear 8 is reengaged with the perforations of the tape ata point in time at 17 milliseconds. These actions take place in the samemanner with every symbol. As shown in FIG. 2, line a represents theperforation stamping motion and line b represents the vertical movementof the tape advancing gear 8.

For continuing the feeding in the forward direction the followingconditions exist (see FIG. 2, line In the rest position the tapeadvancing gear 8 lies against the forward limit stop 11 and is in meshwith the feed perforation; For successive forward feeding, the armatureblade 24 lies against the limit stop 27 and the tape advancing gear 8movement is controlled by the lever 14. The reverse movement of the tapeadvancing gear 8 below the perforated tape occurs within the time periodfrom to 10 milliseconds until the tape advancing gear 8 lies at therearward limit stop 10. The advance of the tape commences atmilliseconds and ends at 27 milliseconds, the terminal position of thetape advancing gear 8 being determined by the forward limit stop 11.

In order to change the direction of feed from forward to reverse (seeFIG. 2, line d) the following occurs. In the rest position the tapeadvancing gear 8 lies at the forward limit stop 11 in mesh with the tape33. The armature blade 24 still lies against the limit stop 27 and thecontrol lever 14 has descended and lies at the bottom of the cam 18. Therearward motion of the tape advancing gear 8 below the tape path occursfrom 5 to 10 milliseconds. The command to reverse generally occursbeginning with the 0 point in time of the diagram; however at the latestit should occur early enough so that the switching of the armature 22 ispossible from a point in time at 5 milliseconds on; it is limited intime (see FIG. 2, line g) by the cam 31 and the spring contacts 32 whichare effective to energize the magnet 23 by the winding 23a. However, thearmature 22 can only be attracted and shifted if the control lever 14 ison top of the camlii (at 9.4 milliseconds) and releases the blade 24.The dead center spring 30 insured a short switching of the blade 24which occurs within 0.5 to l millisecond. The control lever 14 isrendered inoperative and the control lever 15 can follow its respectivecam 19 within the time period from 11 to 16 milliseconds and can advancethe tape advancing gear 8 below the tape path from the rearward limitstop 10 to the forward limit stop 11. The feeding movement in thereverse direction occurs by reason of the force of the torsion spring 12between the points in time of 20 milliseconds and 27 milliseconds; andthe tape advance gear 8 remains at the rearward limit stop 10 in thetape.

If continuous reverse feeding is to occur (see FIG. 2, line a) thefollowing takes place. The tape advancing gear 8 is, in the restposition, at the rearward limit stop 10 and is in mesh with the feedperforation. Upon continuing reverse feeding, the armature blade 24 liesagainst the limit stop 26 and the tape advance gear 8 movement iscontrolled by the lever 15. The forward movement below the tape pathtakes place within the time from 11 milliseconds to 16 millisecondsuntil the tape advancing gear lies at the forward limit stop 11. Therearward feed occurs between 20 milliseconds and 27 milliseconds untilthe tape advance gear 8 reaches the limit stop 10.

When the feed direction is to be changed from reverse to forward, (seeFIG. 2, line 7) the following occurs. The tape advancing gear 8 lies inits rest position at the rearward limit stop 10 in mesh with the tape33. The armature blade 24 lies against the right hand limit stop 26 andthe control lever 15 is on top of the cam 19. The control lever 14supports itself on the armature blade 24. When the command feed forwardoccurs, by reason of the cam 31 and the spring contact 32 at 5milliseconds, the winding 23b of the magnet 23 is energized and thearmature blade 24- switches positions. This occurs if the rollers 16 ofthe control lever 14 lies on the top of its respective cam 18 atapproximately 9.4 in time thereby permitting the armature blade 24 toadvance to the limit stop 27. The control lever 15 is thereby preventedfrom descending and the control lever 14 again takes over theadvancement of the tape within the time period from 20 milliseconds to27 milliseconds. The switching of the armature 22 is shown in line h ofFIG. 2.

Particular advantages can be obtained with the aid of the abovedescribed apparatus according to the invention by providing the errorscanning device 38 for scanning the last perforated row in the adjacentperforation row. The error scanning device 38 is associated with theperforation means 1 for the purpose of supervision. More particularly,it is possible within the framework of the subject apparatus to carryout the supervisory scanning within the range of 2730 milliseconds onthe diagram of FIG. 2. In FIG. 2 in line a it is shown in broken linesthat the scanning can take place, for example, at 29 milliseconds of thediagram. Upon ascertaining an error, a return command can be emitted bythe error scanning device 38 which will lead to the initiation of areverse feed during the immediately following perforation cycle. Thus,no additional time is needed for the change in the feeding direction.

I claim:

1. Apparatus for two directional feed of perforated tape, whichcomprises:

a tape advancing gear (8) mounted for engagement and disengagement inthe perforations of the tape; means (3, 4, 7) for cyclically engagingand disengaging said gear in said tape perforations;

a first lever (14) for advancing said gear in a forward direction whenthe gear is in engagement with the tape;

a second lever (15) for advancing said gear in a forward direction whenthe gear is disengaged from the tape;

means (20, 21) for normally biasing said first and second levers towardan operative position with respect to said gear;

means (24) for blocking one or the other of said levers to render thatparticular lever inoperative;

a drive shaft (2) having two spaced cams (18, 19) mounted thereon, saidcams being transposed with respect to their angular position and saidcams being designed to alternately urge said levers away from said gear;

means (12) for biasing said gear in a direction opposite to theadvancement imparted thereto by said levers to return said gear aftereach cycle, said last mentioned biasing means (12) being weaker than thebiasing means (20, 21) of said levers; and

means (23) for controlling said blocking means to determine which leveris rendered inoperative and thereby control whether the tape is advancedin a forward or a reverse direction;

whereby rotation of said cams (18, 19) causes one or the other of saidlevers (14, 15) to advance and then permit retraction of said gearthereby advancing the tape in either a forward or reverse directiondepending on whether the gear is engaged in the perforrations when oneof said levers advances or is engaged in the perforations when said gearbiasing means (12) returns said gear.

2. Apparatus as recited as in claim 1 wherein said lever biasing means(20, 21) comprises tension springs and said gear biasing means (12)comprises a torsion spring having approximately one-half the strentgh ofsaid lever biasing means.

3. Apparatus as recited in claim 1 wherein said means for controllingsaid blocking means comprises:

an electromagnet (23) having an armature (22), the

of said levers (14, 15) in an inoperative position; and which furthercomprises:

a dead center spring (30) associated with the free end of said blade toprevent the armature from remaining in an intermediate position; andwherein said electromagnet further includes:

two alternately energizable windings (23a, 23b) for controlling theposition of said armature to determine which of said levers is blockedin an inoperative position.

5. Apparatus as recited in claim 1, which further comprises:

a first limit stop (10) for limiting the movement of the gear (8) bysaid gear biasing means (12); and

a second limit stop (11) for limiting the movement of the gear by saidfirst and second levers 14, 15

6. Apparatus as recited in claim 5 wherein said limit stops (10, 11) aremounted on eccentrics (36, 37) for adjustment of the position thereof.

7. Apparatus as recited in claim 3 wherein said cams (18, 19) and saidengaging and disengaging means (3, 4, 7) for said gear (8) are designedso as to provide a pause between the time periods during which said gearis advanced in one direction or the other, during which pause said means(31, 32) for supplying electric pulses to said electromagnet (23), canoperate to change the setting of said blocking means (24) therebyreversing the direction of feed of said perforated tape.

8. Apparatus as recited in claim 7 which further comprises:

error scanning means (38) for sensing an error in perforations, saidmeans being connected to said means (32) for supplying electric pulsesto said electromagnet and being operable to reverse the direction offeed of the perforated tape during the next succeeding perforation cycleupon the sensing of an error.

References Cited UNITED STATES PATENTS 2,933,931 4/1960 Lisinski.

3,292,832 12/1966 Drillick 22649 X M. HENSON WOOD, JR., Primary ExaminerR. A. SCHACHER, Assistant Examiner US. Cl. X.R. 22662

